This invention relates to concrete finishing machines and more particularly to a concrete finishing machine including an adjustable auger unit.
In many concrete finishing machines, it is common practice to employ one or more augers mounted forward of the finishing unit which may comprise a screed mechanism or finishing cylinders. The augers are arranged and formed such that rotation of the augers during operation of the machine causes the augers to move concrete toward the space between the augers as well as longitudinally outwardly from the augers away from the finishing unit. In this manner, excess concrete is plowed forward on every pass. The augers on the concrete finishing machine are adjusted to leave the proper amount of concrete at the leading edge of the finishing unit to obtain the best finish.
In one known concrete finishing machine disclosed in U.S. Pat. No. 4,068,970 in which the finishing unit includes a screed mechanism, the augers comprise an assembly separate from the screed mechanism and driven through a separate motor. This arrangement enables the auger unit to move independently of the screed mechanism and permits independent adjustment of the auger relative to the screed mechanism, but adds the complexity and cost of the additional drive for the auger unit.
In other known concrete finishing machines of the type employing finishing rollers, a pair of horizontally extending augers are connected directly and non-adjustably to the output shafts of a pair of finishing rollers and driven thereby. In order to leave enough concrete for finishing with this machine it is necessary to raise the front edge of the augers which raises the rollers and takes them off grade. This also has the effect of lowering the rear end of the rollers which leaves a mark in the concrete. Both results are unsatisfactory. Additionally, adjustment to establish the desired grade, requires raising the rearward edge of the finishing cylinders vertically upward relative to the leading edge of the cylinders. This adjustment causes the forward end of the augers to be pivoted downward so that less concrete than desired is pulled from the forward edge of the cylinders to the forward end of the finishing carriage. This requires adjustment of the height of the auger unit which disturbs the previously set finishing grade height and disturbs the correct concrete grade.
Thus, it would be desirable to have a concrete finishing machine including an auger unit having one or more augers driven directly by one or more finishing rolls, and wherein the angle of inclination of the augers relative to the axis of the finishing rollers is adjustable independently of grade adjustments made to the finishing rolls.